1. Field of the Invention
The present invention relates to a motor driving device and a method of controlling the same.
2. Description of the Related Art
Recently, electric devices or electronic devices have been increasingly used domestically, commercially and industrially due to high demand therefore. Such devices may employ a driving circuit for driving a particular operation. For example, a motor may be used therein.
In general, a brushless direct contact (BLDC) motor refers to a DC motor having a function of applying a current or adjusting a current direction by using a contactless position detector and a semiconductor device without using a mechanical contact unit such as a brush, a commutator, or the like.
A BLDC motor is driven such that a current is applied in two phases among three phases to drive a switch, while one phase is open, according to a position of a rotor of a permanent magnet by using an inverter circuit. To this end, in the BLDC motor, a phase current of the motor should be changed according to a position of the rotor, so a rotor position detection sensor such as a hall sensor, an encoder, or the like, is required. Also, research into the development of a sensorless drive or driving a BLDC motor without a position sensor such as the hall sensor, the encoder, or the like, has been actively conducted.
A BLDC motor includes an electronic commutating unit installed instead of a brush and a commutator of a DC motor, providing advantages such as high efficiency, compactness, and the like, and therefore, it is used in various fields such as an ultra-book, a low-voltage fan, and the like. In particular, a motor driver IC driving current tends to be lowered for an ultra-book or a low-voltage fan. For example, in the case of a 5V fan motor, current consumption characteristics of about 1.3 mA are required, excluding a driving current. In the case of motor driving, since all circuits are constantly operated, a current is to be constantly applied, thus being ineffective in terms of power.